In a major setback for prosecutors, a federal jury failed yesterday to reach a verdict in the trial of a key money laundering suspect in an international Nigerian credit card fraud ring, forcing a mistrial in the case.

After a 5-week trial in Baltimore and after deliberating for more than 20 hours, jurors told the judge they were deadlocked at 11 to 1 in favor of convicting Nigerian national Abiodun Bashorun, a man prosecutors portrayed as the Chicago-based link in the ring that stretched from California to Maryland to West Africa.

The lone juror held out because she did not believe prosecutors proved that Bashorun knew he was laundering nearly $450,000 worth of fraud proceeds for the ring, several jurors said late yesterday. Bashorun maintained that he thought he was doing a friend a favor by handling the money.

"I'm just thankful to Jesus," Bashorun said afterward. "He knows the truth."

"Our case will only get stronger," said Robert R. Harding, another prosecutor in the case.

Bashorun was indicted in Baltimore last year along with 12 other Nigerian nationals. They were charged with stealing the identities of unsuspecting victims, applying for credit cards and bank accounts in their names, and then going on spending sprees that reached into the millions.

The proceeds of the ring, along with the proceeds of heroin trafficking, were then sent to ring members in Maryland and Washington, who wired them to accounts and corporations in Africa, South Korea, the Far East and Eastern and Western Europe.

The case provided a look at a burgeoning problem for law enforcement officers around the country -- credit card fraud carried out by secretive Nigerian organized crime organizations that are loosely affiliated and well insulated from outsiders.

The first trial in the Baltimore case began more than five weeks ago with Bashorun and five other defendants. Before a witness took the stand, four of the suspects pleaded guilty. After a few weeks, a fifth man pleaded guilty to money laundering and heroin trafficking. The other defendants named in the indictment are awaiting trial, extradition or are fugitives.

That left Bashorun alone at the defense table.

Prosecutors told jurors that Bashorun laundered nearly $450,000 worth of credit card fraud proceeds for the ring from his Chicago base, and they introduced more than 400 exhibits into evidence to document the paper trail.

Bashorun testified that he was nothing more than a hard-working social worker who had been hoodwinked by his boyhood friend from Nigeria, Adeniyi Allison. Considered by prosecutors to be the leader of the organization, Allison is being held in England pending extradition to the United States.

"Have you ever put money in a bank account to conceal any kind of reporting requirements?"

"All of the money I received I put into the account," he said.

Bashorun said he and Allison grew up together in Nigeria. Bashorun moved to Maryland and then to Chicago. Allison also moved to the United States and asked Bashorun to do him a favor. Allison said he wanted Bashorun to help send money back to friends in Africa.

"Did you have any reason to believe this money was illegally obtained?" Cheslock asked.

"No," Bashorun said.

After four days of deliberations, the jurors told U.S. district Judge Catherine C. Blake that they were deadlocked.

Minutes after Blake dismissed the jurors, Sale, Harding and Cheslock met them to discuss their deliberations. The prosecutors asked the jurors what they could do at the next trial to improve their chances.

"Anything that speaks to his [Bashorun's] frame of mind would be helpful," foreman James Russell said. "Personally, I didn't need it."